Abstract
The inflorescence of rice consists of several rachis branches. Meristems produced on the branch acquire the identity as a spikelet meristem (SM). SM differentiates a flower and terminates its growth. The timing of the phase transition to the SM is a major determinant of the rice inflorescence structure. It was reported that PAP2 accelerates the acquisition of the identity as a SM. On the other hand, APO1 and RFL suppress the SM identity. The purpose of this study is to clarify the mechanism regulating meristem phase change through the analysis of molecular functions of APO1 and RFL.
APO1 physically binds with RFL and functions interdependently. The expression of APO1 initiates in the inflorescence meristem (IM) after the transition to the reproductive phase and activates cell proliferation in IM. We carried out transcriptome analysis of genes specifically expressed in IM at early stages of inflorescence development by using LMD-microarray. It was shown that RFL and MADS-box genes related to floral transition were identified in this analysis, indicating the validity of this method. Isolation of genes under the control of APO1 by using same LMD-microarray system is in progress.
